Speaker
Description
Deceleration of heavy polar molecules is one of the critical steps toward future searches for the electric dipole moment (EDM) using molecules [1], enabling extended coherence times or efficient trap loading. Among various techniques developed for molecular slowing, such as laser slowing [2], Stark deceleration [3,4], and Zeeman Sisyphus methods [5], centrifuge deceleration [6] offers distinct advantages. It is insensitive to molecular internal structure and operates continuously, making it well suited for diverse species and compatible with Cryogenic Buffer Gas Beam (CBGB) sources. However, its application to heavy molecules remains unexplored. We performed a Monte-Carlo simulation of centrifuge deceleration for heavy polar molecules to investigate the feasibility of this scheme for future EDM searches. The molecule studied is tungsten monocarbide (WC), which has a 3Δ1 electronic state, preferred state for electron EDM measurement for the same reason as ThO [8] and HfF+ [9]. In WC, the 3Δ1 electronic state is the ground state, allowing the decelerated beam to achieve longer coherence times.
The simulation result is shown in Fig. 1. Our results demonstrate that, for an initial peak velocity below 135 m/s, a decelerator with a 40 cm radius can decelerate the molecules to below 30 m/s with an efficiency of ~0.1 %. We also found that YbF, another EDM measurement candidate, can be decelerated under similar conditions. These findings highlight the potential of centrifuge deceleration as a practical and versatile tool for future EDM measurements.
[1] R. Alarcon et al., arXiv:2203.08103 (2022).
[2] N.J. Fitch and M.R. Tarbutt, Advances in Atomic, Molecular, and Optical Physics 70, 157 (2021).
[3] D. Reens et al., PRR 2, 033095 (2020).
[4] P. Aggarwal et al., PRL 127, 173201 (2021).
[5] H. Sawaoka et al., PRA 107, 022801 (2023).
[6] X. Wu et al., Science 358, 645 (2017).
[7] M. Koller et al., PRL 128, 203401 (2022).
[8] ACME Collaboration, Nature 562, 355 (2018).
[9] T.S. Roussy et al., Science 381, 46 (2023).
